Abstract3.1 Introduction3.2 Graphene and its derivatives3.3 Fabrication, structure, properties, and toughening mechanisms of epoxy composites containing GnPs of ~10 nm in thickness3.4 Fracture mechanisms of epoxy/GnPs nanocomposites—fabricated by a thermal-sonication approach3.5 Toughening mechanism of epoxy composites containing long-chain modified GnPs of ~ 3 nm in thickness3.6 Fabrication, structure, property, and toughening mechanism of epoxy composites containing GnPs, which are reactively modified3.7 Conclusions and challenges